Bayek becomes the first Mentor of the Assassins in Assassin's Creed Origins.
Bayek of Siwa and his wife Aya establish the Hidden Ones after fighting the Order of the Ancients. The Hidden Ones are the direct precursor to the later Assassin Brotherhood, so Bayek is treated as one of its founding figures. The game presents the order's early principles, including resistance to domination and the protection of ordinary people.
Bayek begins as a Medjay, a protector and law-enforcement figure serving the local community in Ptolemaic Egypt. His personal search for the people responsible for his son's death gradually develops into a broader political and ideological struggle. Aya becomes equally important to the organization's creation, even though Bayek is the character identified with its first Mentor role.
Altaïr leads a much later Levantine Brotherhood, Shay is the former Assassin protagonist of Rogue, and Connor is the central Assassin in Assassin's Creed III. None of those characters founded the organization in Egypt.